"The message is much simpler," Biddle said. "If it's a consumer products package, it's recyclable. That's what we've done with our system."
Officials are so pleased with the growth of recycling - the rate was 7 percent in 2008 - that they have begun to reconsider what to do with the rest of the trash.
The city recently sought proposals for evaluating the environmental and fiscal implications of building a waste-to-energy plant. In the past, this meant incineration.
Now, said Rina Cutler, deputy mayor for transportation and utilities, "we are pretty convinced that the technology has so significantly changed . . . that we think it is something we should at least seriously take a look at."
She said she was not yet sure whether she would recommend it. No potential site has been identified. Nor is it clear if the city would build and own a facility, or have someone else do it.
Joseph O. Minott, executive director of the Clean Air Council, said he was skeptical. "Certainly there are different models out there, but I have yet to see one that does not emit air pollution and create a hazardous waste," he said.
Others say the city should instead take the next step in recycling, albeit not an easy one - adding a collection system for organic material that can be composted, 34.8 percent of the city's waste stream.
"If we added composting to our collection at the curb, we'd get to 40 percent in a hurry," said Maurice Sampson II, president of Niche Recycling Inc., a longtime Philadelphia recycling advocate.
The U.S. Environmental Protection Agency's hierarchy of solid-waste management puts source reduction at the top, recycling and composting in the middle, disposal in landfills or combustion facilities at the bottom.
